Forming the belt buckle housing from two housing shells that are joined together by welding is known from the prior art. Providing opposite fixing projections on the housing shells for joining the shells together is also known (DE 43 10 9 28 C2). In the assembled state, the fixing projections have aligned openings into which a lock pin is inserted.
The object of the invention is to provide a belt buckle of the kind initially specified, in which the two housing shells can be joined securely together in a simple manner to form the housing.
This object is achieved according to the invention by claim 1. Advantageous developments of the invention are defined in the dependent claims.
In the invention, the at least two housing shells from which the housing is formed are joined at their shell rims. Elongated cover strips made of solid material and covering the mutually abutting rims of the housing shells are fixed to the joined housing shells. The cover strips may preferably be adapted to secure the housing shells to each other against a disconnecting movement.
The at least two housing shells may be joined to each other by welding them together at their rims. The resultant weld seams are covered by the cover strips. The at least two housing shells may preferably have engaging members at their shell rims, which by means of a particular movement can be brought into engagement with each other. By this means, the at least two housing shells are joined together.
It is also possible that the elongated cover strips are moulded integrally onto one of the two housing shells.
The engaging members are preferably embodied in such a way that they overlap in their engaged position, and that the housing shells are joined to each other by a movement substantially parallel to the rims of the housing shell.
The engaging members may have stop faces which prevent a sliding movement transverse to the movement with which the housing shells are joined to each other.
Securing members which are in engagement with corresponding securing members formed on the joined housing shells may be provided on the inner surfaces of the cover strips, facing the joined housing shells. This causes the joined housing shells to be secured to each other against a disconnecting movement.
The cover strips may also be embodied as clamp members, the clamping engagement of which on the joined housing shells preventing any disconnecting movement of the housing shells. This securing against the housing shells coming apart can also be achieved by the cover strips not only being embodied as clamp members, but also having the securing members which engage with the securing members formed on the housing shells.
In order to fix the cover strips onto the joined housing shells, they may be attached to a ring which is pushed over the joined housing shells. The cover strips and the ring are preferably of one-piece construction. The cover strips and the ring may of metal or plastic.
Another advantageous embodiment of the invention is when the housing shells forming the housing each have a surface covering, the abutting edges of which, when the housing shells are joined together, are covered by the cover strips.
The surface covering may be made of a different material from that of the housing shells, in particular of a decorative material. Suitable decorative materials include, for example, leather, textile fabric, films, carbon fibre fabric, plastic, metal and the like. The surface covering may be embodied in the form of an overlay. The surface covering is preferably embodied as a shaped body, in particular as a cover shell. The shape of the shaped body or cover shell is adapted to the outer surface of the housing shells. The surface covering preferably consists of a sound-absorbing material. Sound-absorbing embossments may be additionally provided on the outer side of the surface covering. However, it is also possible to achieve sound absorption by the embossments on the surface covering.
The pushbutton of the belt buckle may likewise have a surface covering, in particular of a decorative material. The pushbutton portion which is located in the insertion opening for a belt tongue joined to the safety belt or which is adjacent to said insertion opening may have a harder surface than the rest of the surface covering disposed on the pushbutton. Operation of the pushbutton can be improved and made more pleasant by means of the surface covering on the pushbutton, said surface covering consisting in particular of a decorative material, and in particular in the pushbutton portion to which pressure can be manually applied.
The harder surface in the region of the insertion opening can also be achieved by post-curing the material of the surface covering. This post-curing can be achieved with a coating which hardens, for example a plastic coating, or by applying a coat of paint or varnish to the surface, or by impregnating the surface.
The invention also relates to a belt buckle for a vehicle safety belt, in which a locking mechanism is provided in the housing, with which a belt tongue which is inserted through an insertion opening and which is joined to the safety belt can be releasably locked. A visual display device is also provided on the housing, which can be perceived outside the housing with the aid of at least one luminous element disposed inside the housing.
Belt buckles in which the lock state of the belt buckle is indicated by the visual display device are known from DE 2003 15 9 58 U1 and DE 10 2010 0 26 913 A1, for example.
The invention differs from the latter by the at least one luminous element being embodied in such a way that the interior portion of the housing immediately adjacent to the pushbutton is illuminated, and in that a translucent gap is formed between the opaque pushbutton and an opaque rim of the housing recess in which the pushbutton is disposed. The housing components adjacent to the illuminated interior portion, and the pushbutton itself, are impermeable to light, so the light can escape from the inside of the housing through the gap only. This ensures that the position of the pushbutton is clearly indicated so as to make it easier to operate, even when visibility is poor, and specifically when it is dark inside the passenger compartment.
The translucent gap is advantageously designed in such a way that it is provided at least at the pushbutton edges on the opaque portion of the pushbutton to which pressure can be manually applied. The geometrical dimensions of the opaque portion of the pushbutton to which pressure can be manually applied and which is used to operate the belt buckle are rendered discernible by this means. The illuminated gap may have be U-shaped, for example, and may form a continuous or a broken illuminated line. The gap may also have a translucent cover at the pushbutton and/or at the edge of the housing recess.
The at least one luminous element may also be configured in such a way that the insertion opening is also illuminated when the belt tongue has been removed.
The at least one luminous element is preferably integrated in a sensor device which detects the lock state of the belt buckle, for example to detect whether the associated motor vehicle seat is occupied or not. For example, the luminous element may be installed in the casing of the sensor device for detecting the lock state, or in the switch or the display device in a way that ensures the housing interior is illuminated in the manner described above.
The at least one luminous element is preferably switched on by opening at least one of the vehicle doors and before the vehicle engine is started. However, it is also possible for the at least one luminous element to be switched on by a switching function that is performed between the latter two actions.
The at least one luminous element preferably remains switched on during the period in which the belt tongue is locked in place in the locking mechanism. This ensures that the geometrical outlines shape of the pushbutton portion to which pressure can be manually applied are clearly indicated for the purpose of releasing the belt tongue from the locking mechanism, so that they are also discernible even when visibility inside the passenger compartment is poor.
Since all that is illuminated when the belt tongue is locked in place is the gap between the pushbutton and the perimeter of the housing recess, and since the insertion opening either alone or in combination with the gap is illuminated when the belt tongue has been removed from the belt buckle, a switching is provided which indicates whether the belt buckle is closed or open.
If necessary, fibre-optic light guides may lead from the at least one luminous element to the gap to be illuminated and/or to the insertion opening to be illuminated, for example with the aid of a fibre optic coupler. It is also possible to provide at least two luminous elements which are assigned respectively to illuminate the insertion opening and to illuminate the gap.
An LED is preferably suitable for the at least one luminous element.